This newsletter covers major developments across data and AI, including DoorDash’s new Write-Ahead Intent Log for scalable CDC, OpenAI’s Kepler AI analyst for massive data insights, and Lyft’s Metric Semantic Layer for unified business metrics. It also reviews ClickHouse ingestion optimizations, DuckDB’s latest release and agent use cases, Databricks’ Lakehouse//RT and LTAP pushes, plus tools for self-healing pipelines and data quality monitoring.

• DoorDash replaced Debezium with a Write-Ahead Intent Log (WAIL) that writes mutation intents to Kafka and the DB, enabling faster recovery and much higher CDC throughput at Cassandra scale
• MotherDuck claims a $2.40/hour DuckDB instance beats a $64/hour Snowflake 2XL cluster by ~5x on ClickBench, with median query latencies of 3ms, positioning DuckDB for fleets of lightweight agent workloads
• Lyft's Metric Semantic Layer assigns dual business/operational ownership to "Golden Metrics" defined in versioned JSON, auto-propagating changes across dashboards, APIs, and AI agents to prevent divergent calculations
• OpenAI's Kepler analyst now operates over 600 PB of data using Codex-based crawlers and AST-normalized LLM grading to infer lineage, freshness, and hidden semantics automatically